Device for connecting electric conductors

Abstract

An ultrasonic welding apparatus for electrical conductors comprising strands of wire comprising a sonotrode for generating ultrasonic vibrations and a cooperating anvil having movable side walls to compress the wire strands against the head of the sonotrode. The anvil has two moving parts, one moving back and forth parallel to the fixed sonotrode face, and the other moving up and down normal to the fixed face. The moving parts carry the side walls of the anvil and with the fixed face provide an adjustable space for wires of various sizes, the space having a rectangular cross section. The gap between the moving anvil parts and the adjacent fixed face of the sonotrode are accurately controlled.

What is claimed is: 
     
       1. In a device for ultrasonically welding electrical conductors comprising a sonotrode which produces ultrasonic vibrations, said sonotrode having a head with a fixed face disposed parallel to the axis of the ultrasonic vibrations, and   an adjustable compression space adjacent said fixed face and defined by anvil faces for retaining and compressing said conductors during the welding process the improvement comprising     a first anvil part slidably mounted for back and forth movement parallel to said fixed face and having a first anvil face at the end thereof disposed at right angles to said fixed face     a second anvil part slidably mounted adjacent said sonotrode head for up and down movement normal to said fixed face, said second anvil part having a projection at its upper end extending into said compression space, the underside of said projection forming a second anvil face parallel to said fixed face and     a third anvil face normal to said fixed face below said projection whereby said compression space is defined by said first, second and third anvil faces in conjunction with said fixed face and is adjustable by moving said first and second anvil parts with respect to said fixed face.   
     
     
       2. The device of claim 1 in which said sonotrode has a body mounted on adjustable pins which bear against opposed sides of said body to permit accurate control of the size of a gap between said fixed face and first anvil part and a gap between said head and said second anvil part. 
     
     
       3. The device of claim 2 in which said gaps are between 0.01 and 0.02 millimeters wide. 
     
     
       4. The device of claim 2 in which said pins are located in the last sound node before the end of said sonotrode head to minimize flexion of said head. 
     
     
       5. The device of claim 1 in which said projection comprises part of a separate crosshead secured to the top of said second anvil part. 
     
     
       6. The device of claim 1 in which said second anvil part consists of a rod on which said third anvil face is located. 
     
     
       7. The device of claim 1 in which said first and second anvil parts are each actuated by a double acting pneumtic cylinder.